White iPhone Is Thicker Than Black iPhone
Steve Jobs and Phil Schiller told us that more work went into the white iPhone 4 than just making it white, and apparently that work involved making it bigger. Many folks reported noticing that the white iPhone was just a touch thicker than the black iPhone, and now, we know exactly how big it is!

Blog TiPb broke out and electronic ruler and measured both the white iPhone and black iPhones, and discovered that the White iPhone is 0.2mm thicker than the Black one. They note Apple.com’s official tech specs don’t break down a different girth for the white iPhone, but it’s quite obvious from looking at it that it is (see picture).
Now, the next issue? Do cases fit? To me, this seems like another unimportant issue that the tech blog world would blow up into something 100 times bigger than it is. (“My case doesn’t fit the new White iPhone, I’m going to file a class action lawsuit against Apple,” etc.) Thankfully, it seems like 99.99% of old iPhone 4 cases fit the new iPhone.
TiPb their own survey and found that all the cases they tested fit, although some, like the Case Mate “Barely There” case ‘barely fit’. I suspect that all cases will fit, although the more stylish ones may have issues.
Jobs and Schiller told AllThingsD that there were a number of issues with the original design of the white iPhone, like discoloration and such. Obviously, whatever material they went with for the final design is coming out just a bit thicker than the black. This really isn’t a big deal, but something interesting to note.
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So it is true, black makes everything slimmer.
[Ed: link removed]
it should read 2 mm or 0.2 cm